The present invention relates to an arrangement for opening and closing of a film sheet cassette, particularly an X-ray film cassette, and to a film sheet cassette provided with this arrangement.
Film sheet cassettes with opening and closing arrangements are widely utilized. A known film sheet cassette has a bottom part, a top part, and a sliding element which is guided on one or two edges of the bottom part, is held in closing position by a spring, and has a hook which in the closing position engages with a pin provided in the top part. Generally, the top part of the film sheet cassette is connected with the bottom part by a hinge at its edge, and closing elements are arranged at a side which is opposite to the side wherein the hinge is provided. Cassettes are also known in which the top part is placed onto the bottom part in parallel direction and connected with the latter by connecting elements provided at at least two opposite sides. In the cassettes of the first mentioned type, several connecting elements are generally provided lengthwise of the connecting side of the cassette. It has been recognized that the known cassettes possess the disadvantage in that there is a danger that such cassettes can be easily opened under the action of impacts delivered in a direction opposite to the opening direction of the sliding element. Also, the probability that during X-ray examination involving manipulation with several cassettes at least one cassette drops on the floor, is relatively high. Opening of the cassette is especially undesirable when it has been exposed inasmuch as the opening of the cassette makes it useless and the patient must be again subjected to X-ray examination involving radiation for the second time.